Fusion gear reducer

Abstract

A fusion gear reducer includes a first-stage gear reduction unit and a second-stage gear reduction unit both in a housing. The first-stage gear reduction unit includes a sun gear, a planet gears support, planet gears spaced around the sun gear and meshed therewith, and a ring gear around the planet gears and meshed therewith. The second-stage gear reduction unit includes spaced rollers arranged as a circle, roller grooves, wells formed on an inner surface of the housing, and a cam surface formed on an outer surface of the ring gear so that the ring gear is output of the first-stage gear reduction unit and input of the second-stage gear reduction unit. The roller grooves are disposed on outer surfaces of the planet gears so that the planet gears are output of the second-stage gear reduction unit. The simplified fusion gear reducer solves the problem of bulkiness of gear reducer.

What is claimed is: 
     
         1 . A fusion gear reducer comprising:
 a housing;   a first-stage gear reduction unit disposed in the housing, the first-stage gear reduction unit being an epicyclic gear train including a planet gears support, a sun gear as an input, a plurality of planet gears equally spaced around the sun gear and meshed therewith, and a ring gear disposed around the planet gears and meshed therewith; and   a second-stage gear reduction unit disposed in the housing, the second-stage gear reduction unit being a harmonic drive including a plurality of equally spaced rollers arranged as a circle, a plurality of roller grooves, a plurality of wells formed on an inner surface of the housing, and a cam surface formed on an outer surface of the ring gear wherein the roller grooves are disposed between the cam surface and the wells, and the rollers are rotatably disposed in the roller grooves and confined by the cam surface, the wells, and the roller grooves;   wherein the ring gear is an output of the first-stage gear reduction unit and an input for driving the second-stage gear reduction unit;   wherein the rollers rotate the roller grooves;   wherein the roller grooves are formed on an outer surface of the planet gears support; and   wherein the planet gears support is an output of the second-stage gear reduction unit.   
     
     
         2 . The fusion gear reducer of  claim 1 , wherein the sun gear, the cam surface, and the rotation center of the roller grooves are configured to rotate around the common axis. 
     
     
         3 . The fusion gear reducer of  claim 1 , wherein the roller grooves are disposed between the cam surface and the wells having the rollers disposed therein. 
     
     
         4 . The fusion gear reducer of  claim 3 , wherein the rollers are pushed by the cam surface to partially dispose in the wells to rotate the roller grooves. 
     
     
         5 . The fusion gear reducer of  claim 4 , wherein the cam surface has two arc members on two annular, outer edges respectively, and wherein the rollers are pushed by the arc members to partially dispose in the wells to rotate the roller grooves. 
     
     
         6 . The fusion gear reducer of  claim 2 , wherein the roller grooves are disposed between the cam surface and the wells having the rollers partially disposed therein. 
     
     
         7 . The fusion gear reducer of  claim 6 , wherein the rollers are pushed by the cam surface to partially dispose in the wells to rotate the roller grooves. 
     
     
         8 . The fusion gear reducer of  claim 7 , wherein the cam surface has two arc members on two annular, outer edges respectively, and wherein the rollers are pushed by the arc members to partially dispose in the wells to rotate the roller grooves.